Many personal care products currently available to consumers are directed primarily to improving the health and/or physical appearance of the skin. Among these skin care products, many are directed to delaying, minimizing or even eliminating skin wrinkling and other histological changes typically associated with the aging of skin or environmental damage to human skin.
Skin is subject to insults by many extrinsic and intrinsic factors. Extrinsic factors include ultraviolet radiation (e.g., from sun exposure), environmental pollution, wind, heat, low humidity, harsh surfactants, abrasives, and the like. Intrinsic factors include chronological aging and other biochemical changes from within the skin. Whether extrinsic or intrinsic, these factors result in visible signs of skin aging and environmental damage, such as wrinkling and other forms of roughness (including increased pore size, flaking and skin lines), and other histological changes associated with skin aging or damage. To many people, skin wrinkles are a reminder of the disappearance of youth. As a result, the elimination of wrinkles has become a booming business in youth-conscious societies. Treatments range from cosmetic creams and moisturizers to various forms of cosmetic surgery.
Extrinsic or intrinsic factors may result in the thinning and general degradation of the skin. For example, as the skin naturally ages, there is a reduction in the cells and blood vessels that supply the skin. There is also a flattening of the dermal-epidermal junction which results in weaker mechanical resistance of this junction. See, for example, Oikarinen, "The Aging of Skin: Chronoaging Versus Photoaging," Photodermatol. Photoimmunol. Photomed., vol. 7, pp. 3-4, 1990, which is incorporated by reference herein in its entirety.
It has now been found that vitamin B.sub.3 compounds, including niacinamide, provide benefits in regulating skin condition previously unrecognized in the art of which the present inventors are aware. For example, topical niacinamide can regulate the signs of skin aging, e.g., reduce or efface the visibility of the fine lines, wrinkles, and other forms of uneven or rough surface texture associated with aged or photodamaged skin. It has also now been found that topical compositions containing a vitamin B.sub.3 compound and a retinoid provide benefits in regulating skin condition previously unrecognized in the art of which the present inventors are aware. For example, such compositions enable the regulation of signs of skin aging with decreased potential for retinoid dermatitis. In addition, the vitamin B.sub.3 compound in combination with certain retinoids synergistically regulates signs of skin aging, especially visible and/or tactile discontinuities in skin texture associated with aged skin, including fine lines and wrinkles.
It is therefore an object of the present invention to provide topical compositions for prophylactically and/or therapeutically regulating mammalian skin condition (especially of human skin, more especially facial skin), containing a vitamin B.sub.3 compound, especially niacinamide.
It is another object of the present invention to provide topical compositions for prophylactically and/or therapeutically regulating signs of mammalian skin aging, containing a vitamin B.sub.3 compound, especially niacinamide.
It is another object of the present invention to provide topical compositions for prophylactically and/or therapeutically regulating visible and/or tactile discontinuities in mammalian skin texture, including fine lines, wrinkles, enlarged pores, roughness and other skin texture discontinuities associated with aged skin, containing a vitamin B.sub.3 compound, especially niacinamide.
Other objects of the present invention are to provide such topical compositions further comprising a retinoid.
The present invention also relates to methods of providing such regulation using the subject compositions.
These and other objects of this invention will become apparent in light of the following disclosure.